1. Field of the Invention
The present invention relates to a chip carrier incorporating an optical semiconductor device or the like mounted thereon, an optical module using this chip carrier, and an optical transceiver.
2. Description of the Related Art
In general, an optical module is formed by incorporating a chip carrier on which an optical semiconductor device or the like such as a semiconductor laser diode (hereinafter, referred to as an LD) is mounted by soldering those onto a package including a power supply terminal, an input signal terminal, a ground terminal, an optical output fiber connector terminal and the like. As the chip carrier, there is used a dielectric material or a semiconductor substrate. The optical semiconductor device is mounted on a ground metal-coated portion, by soldering, formed on the surface of the dielectric material or semiconductor substrate, and the optical semiconductor device is then connected with a high-frequency transmission line or the like formed on the same substrate surface through wire-bonding.
With increase of operating speed in relation to the optical semiconductor device in recent years, excellent high-frequency characteristics have also been demanded with respect to the chip carrier. As a structural example of the chip carrier aiming at an improvement in the high-frequency characteristics, JP-A-10-275957 discloses a structure in which a conductive substrate having an optical semiconductor device mounted thereon is incorporated with a dielectric material or a semiconductor substrate having a high-frequency transmission line and a terminating resistor arranged thereon.
In an ordinary chip carrier using only a dielectric material or a semiconductor substrate, excellent characteristics are hard to be obtained in a high-frequency domain of 20 GHz or above.
Further, in such a chip carrier in which the conductive substrate and high-frequency transmission substrate are separately provided as disclosed in JP-A-10-275957, although high-frequency characteristics are relatively good, there is a problem that its manufacturing cost is high because of its structure, and a packaging process requires much time.